Lithium iron phosphate batteries have the characteristics of "good stability, easy processing, and strong electrical characteristics", and have become a major trend in the development of rechargeable power batteries. However, in the production process of its raw material iron pho

　　Lithium iron phosphate batteries have the characteristics of good stability, easy processing, and strong electrical characteristics, and have become a major trend in the development of rechargeable power batteries. However, in the production process of its raw material iron phosphate, a large amount of nitrogen-containing phosphorus-containing wastewater will be generated. Since N and P are prone to eutrophication of water, they have received special attention in the discharge standards of this type of wastewater. The problem of iron phosphate wastewater treatment should not be underestimated.

　　The total phosphorus content in the mixed wastewater in general iron phosphate production is 450~600mg/L, and they all exist in the form of phosphate. The content of ammonia nitrogen is relatively high. In 1 The pH value of the wastewater is between 1.5 and 2.5, and the TDS content is 30,000 mg/L-50,000 mg/L.

　　At present, biological methods are common in the wastewater treatment methods for iron phosphate production. However, when treating wastewater with biological methods, the iron phosphate production wastewater contains a higher content of sulfate and a small amount of metal ions, which are inhibitors of microbial growth, and pretreatment is required before biochemical treatment. During the later biochemical treatment, appropriate carbon sources need to be added to adjust the appropriate pH to enable microbial growth. The addition of a large number of exogenous substances increases waste. The cost of water treatment, so this type of wastewater is not suitable for biological treatment.

　Lightlyde uses pretreatment + multi-stage membrane concentration + MVR scheme for treatment of iron phosphate wastewater, pure water (PH6-7, conductivity ≤10μs/cm) to reuse, and MVR crystallizes salt. First remove iron, manganese, magnesium, and calcium, concentrate with preconcentrated RO film to 35g/L salt concentration, then mix with the wastewater treated with the mother liquor and send it to the primary and secondary membrane concentration system to concentrate to 160g/L sulfate concentration, and then evaporate and concentrate; primary and secondary membrane concentration systems The water produced in the intermediate RO system is desalted, mixed with pre-concentrated RO water produced and evaporated condensed water and purified by desalting R0 to meet the water reuse standard.

　　This solution is applied to the membrane separation process, which will ensure the water quality of the effluent. Selecting high-quality accessories with reliable quality can ensure the continuous operation of the equipment. The design concept of system integration reduces investment costs. During the operation of the system, it ensures low energy consumption and few consumables, which greatly reduces operating costs. It is one of the most widely used solutions in the treatment of iron phosphate wastewater.